Nav: Home

New patch boosts brightness in medical diagnostic tests

July 09, 2018

Fluorescence-based biosensing and bioimaging technologies are widely used in research and clinical settings to detect and image various biological species of interest. While fluorescence-based detection and imaging techniques are convenient to use, they suffer from poor sensitivity. For example, when a patient carries low levels of antigens in the blood or urine, the fluorescent signal can be feeble, making visualization and diagnosis difficult. For this reason, fluorescence-based detection is not always preferred when sensitivity is a key requirement.

A multidisciplinary team at Washington University in St. Louis and the Air Force Research Laboratory (AFRL) at Wright-Patterson Air Force Base has developed a high-tech fix that utilizes metal nanostructures to increase the fluorescence intensity by 100 times in these diagnostic tests. It's a cheap and easy solution to what's previously been a vexing diagnostic problem.

"Using fluorescence for biodetection is very convenient and easy, but the problem is it's not that sensitive, and that's why researchers don't want to rely on it," said Srikanth Singamaneni, professor of mechanical engineering & material science at the School of Engineering & Applied Science.

As the team recently explained in the journal Light: Science and Applications, techniques to boost the signal -- such as relying on enzyme-based amplification -- require extra steps that prolong the overall operation time, as well as specialized and expensive read-out systems in some cases.

However, the "plasmonic patch" developed by Singamaneni and co-workers doesn't require any change in testing protocol. The patch is a flexible piece of film about a centimeter square, embedded with nanomaterials. All a researcher or lab tech needs to do is prepare the sample in the usual method, apply the patch over the top, and then scan the sample as usual.

"It's a thin layer of elastic, transparent material with gold nanorods or other plasmonic nanostructures absorbed on the top," said Jingyi Luan, a graduate student in the Singamaneni Lab and primary author of the manuscript. "These nanostructures act as antennae: they concentrate light into a tiny volume around the molecules emitting fluorescence. The fluorescence is dramatic, making it easier to visualize. The patch can be imagined to be a magnifying glass for the light."

Singamaneni said the newly developed patch is a cheap fix -- costing only about a nickel per application -- and one that contains not only research applications but also diagnostics. It could be particularly useful in a microarray, which enables simultaneous detection of tens to hundreds of analytes in a single experiment.

"The plasmonic patch will enable the detection of low abundance analytes in combination with conventional detection methodologies, which is the beauty of our approach," said Rajesh Naik, chief scientist of AFRL's 711th Human Performance Wing.

"It's a last step, just like a Band-Aid," Singamaneni said. "You apply it, and the dimness problem in these fluorescence-based detection methods is solved."
-end-
This work was supported by the National Science Foundation (CBET1254399), National Institutes of Health (R21DK100759 and R01 CA141521) and the Barnes-Jewish Hospital Research Foundation. Support also was received from Washington University's Office of Technology.

Jingyi Luan, Jeremiah J. Morrissey, Zheyu Wang, Hamed Gholami Derami, Keng-Ku Liu, Sisi Cao, Qisheng Jiang, Congzhou Wang, Evan D. Kharasch, Rajesh R. Naik and Srikanth Singamaneni. Add-on Plasmonic Patch as a Universal Fluorescence Enhancer. Light: Science & Applications accepted article preview 27 April 2018; DOI: 10.1038/ s41377-018-0027-8.

Washington University in St. Louis

Related Gold Nanorods Articles:

California's other gold
Sea urchin roe is an acquired taste. Served as sushi, uni -- the Japanese word for this delicacy -- is actually the reproductive organ of the sea urchin.
Mining for gold with a computer
Engineers from Texas A&M University and Virginia Tech report important new insights into nanoporous gold -- a material with growing applications in several areas, including energy storage and biomedical devices -- all without stepping into a lab.
A novel way of creating gold nanoparticles in water
The discovery that water microdroplets can replace potentially toxic agents in the creation of gold nanoparticles and nanowires could help usher in a new era of 'green chemistry.'
Using gold nanoparticles to destroy viruses
EPFL researchers have created nanoparticles that attract viruses and, using the pressure resulting from the binding process, destroy them.
Researchers find simpler way to deposit magnetic iron oxide onto gold nanorods
Researchers have found a simpler way to deposit magnetic iron oxide (magnetite) nanoparticles onto silica-coated gold nanorods, creating multifunctional nanoparticles with useful magnetic and optical properties.
Sifting gold from the data deluge
Next-generation DNA sequencing technologies have flooded databases and hard drives worldwide with large data sets, but are researchers getting the most they can out of this deluge of data?
A dash of gold improves microlasers
By attaching gold nanoparticles to the surface of a microlaser, researchers in the USC Viterbi School of Engineering demonstrated a frequency comb that takes up less space and requires 1000 times less power than current comb technology.
Self-healing gold particles
Self-healing materials are able to repair autonomously defects, such as scratches, cracks or dents, and resume their original shape.
Good as gold
Few experiences invoke as much anxiety as a call from your doctor saying 'you need to come back for more tests.' Your imagination goes wild and suddenly a routine medical screening becomes a minefield of potential life-threatening diseases.
When gold turns invisible
A gold compound shifts from a visible fluorescence to emitting infrared when ground -- a big shift with potential applications in bioimaging and security inks.

Related Gold Nanorods Reading:

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Anthropomorphic
Do animals grieve? Do they have language or consciousness? For a long time, scientists resisted the urge to look for human qualities in animals. This hour, TED speakers explore how that is changing. Guests include biological anthropologist Barbara King, dolphin researcher Denise Herzing, primatologist Frans de Waal, and ecologist Carl Safina.
Now Playing: Science for the People

#SB2 2019 Science Birthday Minisode: Mary Golda Ross
Our second annual Science Birthday is here, and this year we celebrate the wonderful Mary Golda Ross, born 9 August 1908. She died in 2008 at age 99, but left a lasting mark on the science of rocketry and space exploration as an early woman in engineering, and one of the first Native Americans in engineering. Join Rachelle and Bethany for this very special birthday minisode celebrating Mary and her achievements. Thanks to our Patreons who make this show possible! Read more about Mary G. Ross: Interview with Mary Ross on Lash Publications International, by Laurel Sheppard Meet Mary Golda...